A radio spectrum resource is a scarce strategic resource. Spectrum resources may be classified into two types: licensed bands and unlicensed bands. For example, spectrum resources used by technologies such as Wireless Fidelity (Wi-Fi) and Bluetooth, are generally open to the public for free and without a need of license, and are referred to as unlicensed bands.
Due to scarcity of the spectrum resources, allocated licensed bands cannot meet future requirements. To obtain new spectrums, unlicensed bands may be used as a beneficial supplement to the licensed bands.
However, unlicensed bands intended to be deployed by a 3rd Generation Partnership Project (3GPP) system have been already deployed/are being deployed in another system. The Wi-Fi technology uses unlicensed bands, such as 5 GHz bands used by 802.11a/n/ac and 60 GHz bands used by 802.11ad.
Generally, a Wi-Fi system includes one access point (AP) and several stations (STAs). In a 3GPP system, spectrum resources are generally used in a synchronization frame-based continuous scheduling manner in which a base station (BS) performs centralized control. In a Wi-Fi system, a technology referred to as Carrier Sensing Multiple Access/Collision Avoidance (CSMA/CA) is used to obtain resources by means of contention. A working principle thereof is: First, the Wi-Fi system waits until a medium (that is, a spectrum) resource is “idle”, then a station (or an access point) starts waiting for a random time period, during which carrier sensing (CS) continues. If the resource still keeps “idle” after waiting time ends, the station starts transmission. The transmission has constraints on a data size and duration. When the constraints are triggered, even if a service still exists, the station needs to contend for a resource again.
A Wi-Fi system uses unlicensed spectrum resources based on a CSMA/CA manner. When interference occurs, the Wi-Fi system actively waits, and evades a signal of the 3GPP system. As a result, the 3GPP system occupies the unlicensed spectrum resources for a long time, whereas the Wi-Fi system is in an interference-evading and waiting state all the time.
To overcome the foregoing technical problem, in the prior art, some subframes are vacated in a frame structure in the 3GPP system and reserved for the Wi-Fi system, and fair use of the unlicensed spectrum resources by the two systems is achieved by adjusting a vacancy rate.
However, in the foregoing technical solution, if the Wi-Fi system does not have or have few service requirements in the subframe, a waste of spectrum resources is caused.